Question 1. Neatly derive the trig identities for cos (u+v) and sin (u+v) using Euler?s Formula: e^i theta= cos theta + i sin theta put derivative here: Question 2. Neatly derive the trig identity cos^2 a = 1+cos (2a)/2 using the sum formula cos (a+b) with b = a. Put derivation here: Question 3. Find sin pi/12 exactly using the appropriate trig identity , using pi/12=pi/3-pi/4, and using values from the table of sines and cosines . Don?t use calculator ! it is OK if there are square roots in your answer. Answer and Work: Question 4. If cos 2 u = root 5/10 find cos^2 u. Do not use your calculator , it is OK to leave square roots in your answer. Answer and Work: